What gearbox did you use for your robots drive train this year?

I just wanted to do a poll inquiring on what gearboxes your team used for your drive-train on your steamworks robot. Please share your experiences with them below.

Our team used the Vex, 2 cim ball shifter. In previous years we used this gearbox and had issues with the bolts holding the cims and shifter on becoming loose. However, this year we fixed that by putting lock tight on all the bolts. We have had no issues this season and plan on using them in future years.

You may vote multiple times if applicable

2910 was very happy with our 3-Cim ball shifters which we cannibalized off our 2014 robot. We had to put new holes in the KoP chassis, but they worked perfectly throughout our season.

WCP 3-CIM DS, here. Though, we had some problems with them and will be investigating the VexPro ball shifters this offseason as a result.

WCP flipped boxes. They were integral to our design and were rock solid through three competitions.

WCP SS. We didn’t use the front plate of it since we have plate drive, so we built it into the plate. No complaints about the gearboxes, they’re simple, reliable, and easy to maintenance (had to swap motors a few times).

If you do decide to use the vex pro ball shifters make sure to locktight the bolts in the 8-32 standoffs holding the pancake cylinder. They come loose really easily and you have to take the whole gearbox apart to fix it. It is a real pain.

Duly noted, thank you very much for the tip!

We ran custom 2 CIM 1 Mini-CIM transmissions. 2 speed using VexPro ballshifters.

Worked quite well for the most part, although we did run into an issue with a ballshifter being almost completely bound in low gear. That was a bit of a frantic fix at Utah :eek:

We used the AndyMark nanotube 31 chassis. I think it was a 12.75:1 reduction. We used 8 inch plaction wheels and we were pretty fast and had decent pushing power.

What if we didn’t use a gear box?

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Don’t make me go find poohbear’s octagon-wheeled monstrosity. I don’t want to do it and you don’t want me to.

Team 8 used two WCP SS Gearboxes with 3 CIMs per side. One issue we had was with the motor mounting system - there are two positions that the motor can be in depending on the pinion gear size, and we found that the motor has a tendency to slip to the unused position. This caused gears to mesh incorrectly and the steel pinions completely chewed away the aluminum input gear. Once the side jammed up we noticed this issue and had to switch out the input gear. Luckily all on the practice bot :slight_smile:

Not to split hairs, the Andymark Kit comes with Toughbox minis, not regular toughboxes.

I assume most kit-bot teams will just check ‘toughbox’, but it’s a different transmission.

We used 4 Toughbox Micros with mecanums.

Andymark EVO-Shifters worked awesomely, the only problem we had was the screw working its way out occasionally. I believe that was fixed with some loctite.

For the sake of simplicity i just bundled all the toughboxes into one. I am aware that there are several varieties but it just makes it simpler in the poll.

WCP 3-CIM DS. 9/10, would do it again (but with steel 14T pinions if RC doesn’t get rid of the snowman holes). We know these gearboxes so well that we did an entire intermediary shaft & gear replacement at champs in under 30 minutes. The shaft twisted & bent under the huge stresses of a major impact at our last event, and the intermediary gear was showing signs of imminent failure.

It’s really tough to say if we’d make adjustments to the gearing, or tried different motors. Given how agile the drive was, we probably could have been fine with 6 MiniCIMs.

4 Versaplanetary Gearboxes - Being able to easily switch them all from 5:1 to 4:1 at our second event was nice. We didn’t have any issues with the gearboxes which were driving 3 omni wheels each. One gearbox does make a slight clicking sound at the same point during rotation, but we haven’t yet opened up the gearbox to see if we can determine what is causing that sound.

1712 has used WCP SS gearboxes for the past three seasons. I’ve liked them enough to keep buying them, as they suit our needs well. In 2015 and 2016 we used 4 CIMs, and in 2017 we used 6 CIMs.

Most of our issues came in 2016. We had a 14:60 2nd stage reduction, powering 7.65" diameter pneumatic wheels. That much torque ending up pushing the aluminum gearing on the 2nd stage to its limit, and we stripped several 14t gears over the course of the year. We switched to steel 14t mid-season, and did not experience another failure (although I suspect it was only a matter of time before we saw a 60t failure, which would have been a much more involved repair). We also managed to blow up a pair of the 0.375"ID bearings during our 2nd event, somehow (I presume at the same time we stripped one of our 14t gears).

Our only issue in 2017 came in our 2nd to last match, where a very hard collision (involving enough force to send us a few inches airborne) caused one of the faceplates to become bent, leaving our output shaft slightly askew. This hasn’t caused any real issues, but it is a matter of concern.

I also echo some of the concerns about the “snowman holes” that JesseK raised.

That being said, I’ve liked them enough to buy them three years in a row. And unless we take the jump into dual-speed in the future (something I have mixed feelings on) or move to something completely aside of tank drive, they’re an early front runner for consideration again next year.

Are all of your problems still related to mounting? I laid out how 1712 traces out our mounting geometry for using the gearbox bearing blocks in this post. Let me know if you have any additional questions.

We ran the Single Reduction Single Speed Gearboxes from VEX again this year. They have been pretty much bulletproof. This year we got some longer standoffs from McMaster and shortened the output shaft.